Modular robots can be used for
everything from search and rescue
operations in piles of rubble to maintenance in pipelines. But what is it that
makes modular robots so useful?

Modular robots have an edge in
robustness, scalability, and adaptability.
Many modular robots are made of
regular modules, more like the Bioloid
than the modified V-Bot. That means
they can be rearranged and reconstructed to create a variety of different
shapes capable of tackling different
tasks. Perhaps a modular bot can start
out as a wheel blazing across flat
terrain and turn into a slithering snake
to deal with uneven surfaces. Our
modified V-Bot couldn’t really do that
— perhaps after modularizing a few
more appendages it could give a passable impression of a Picasso painting,
but not too much else (maybe Dalí).

Fancy modular robots are also
able to attach and reattach modules
dynamically. Sometimes this is accomplished using shape memory alloys at
the interface between modules, or
perhaps even just mechanical latches.
The V-Bot couldn’t ditch its arm in a
heartbeat, because screws have to be
undone and the connector disconnected. But if the V-Bot was to break an
arm by performing a karate chop on
the wrong robot, it would be quick to
amputate the damaged limb and,
assuming we had another module at
the ready, outfit it with a new one.
That gets to the heart of one of the
great advantages of modular robot
design — robustness. A modular robot
can simply leave behind damaged
modules, and though that might seem
a bit coldly utilitarian, it’s certainly a
much more favorable outcome than
having one faulty bit take out the
entire bot.

Another major advantage of
modular robots is in scalability.
Regular modules can basically be
interchangeable parts, so such bots
would be easy to mass produce. It can
also be a great way to prototype —
make a smaller version of a final bot
that’s smaller in the sense that it just
uses less modules. By the same token,

modular bots are also easy to expand
and modify. To add a sensor, all you
would have to do is add another
module instead of cracking the whole
thing open and wondering how to
make it all fit together.

For all of these advantages, it
would seem like every robot should
be modular, but there are some
design hurdles that also make them
as intimidating as they are appealing.
For one, to make truly independent
modules, they all need to have their
own power sources. When you’re
dealing with a lot of modules, that
can start to get a bit hairy. Also, truly
independent modules would all need
their own processors, and if you want
them to be equipped with sensors or
some other sort of mechanical
device, it’s starting to look like a lot of
things to include in a single module.
The modular unit might be very
difficult to design, but the potential
rewards are certainly enough to have
a lot of very smart people trying to
solve the problem.

So, in the end our modified V-Bot
might not have been a great example
of a modular robot, but that doesn’t
detract from its overall coolness, even if
it might be more of a toy than a robot.
The V-Bot does not have any external
sensors, so in that sense it doesn’t even

V-BOT KARATE!!

skirt the formal definition of a robot. It
does, however, look like what many
people expect a robot to look like, and
it acts like what many people expect a
robot to act like.

However inaccurate this concept of
robots propagated by children’s toys
and summer blockbusters may be, we
think the V-Bot does a good job of
capturing the essence of that popular
conception. We were also very
impressed by the V-Bot’s sophistication
and apparent hackability, so we wouldn’t be too surprised to see it rear its
head in the magazine in the future (to
thumping techno beats, of course). SV